Railway signaling



Nov. 19, 1929.

' C. W. BELL RAILWAY SIGNALING Filed Feb. 16, 1929 INVENTOR PatentedNov. 19, 1929 UNITED STATES PATENT OFF ICE.

CHARLES W. BELL. F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH &v SIGNALOOIEPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

RAILWAY SIGNALING Application. filed February 16, 1929'. Serial No.340,453.

My invention relates to railway signaling, and particularly to means forselecting the controls for railway signals-according to the direction oftrafiic movements over the stretch of track'with which such signalsaretrol of railway signals.

I will describe one form of apparatus embodying my invention, and willthen point out thenovel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of;apparatus embodyingmy invention.

Referring tothe drawing, reference character Y designates a; stretchofrailway track with which a passing siding Z is connected by manuallyoperable switches F and F Rails 1 and 1 of stretch Y are divided bymeans of insulated joints 2. into sections AB, B-C and CD. Each of thesesections is provided with a; track circuit which is supplied withcurrent bya battery 3 connected across the rails adjacent one end of thesection, and which includes a relay designated by the reference,character G} with a distinguishing sufiix and connected across the railsadjacent the-opposite endof the section.

Two signals each of which is designated by the letter S with adistinguishing sufiix, are located on opposite sides of the trackadjacent each pair of insulated joints 2 at points A, B, C and D. Ashere shown, these signals are of the semaphore type and are capable ofdisplaying any one or three indications,

namely, high speed, reduced speed, and stop. The high speed and. reducedspeed indications will hereinafter be referred to as the proceed andcaution indications, respectively. Signals S S, S and S- governwestbound tralfic, that is, traflic moving toward the left as shown inthe drawing, and signals S S*, S and S7 govern eastbound traffic, thatis, traflic moving toward the right as shown in the drawing.

My invention is completely illustrated by the control circuits as shownfor signals S and S"; Signals S and S may be controlled similarly,respectively, to signals S and S Signals S S S and S may be controlled,similarly to corresponding signals in a well known system of signalingwhich is called absolute permissive block signaling.

Polarized line relays, designated by the reference character H with adistinguishing suifix, are shown for signals S S 'and S, but thecomplete circuits for such relays are shown only in connection withsignals S and S The control for relay H may-be similar to that which isprovided. for a similar relay controllinga corresponding signal inabsolute permissive block signaling. A slow release relay P iscontrolled by a. front contact of relay H A stick relay T is arranged tobecome ener-.

gized when a westbound train passes signal Si, and to continue energizedwhile the train is proceeding through section AB.

Relay H? is operated by direct current of normal or reverse polaritysupplied to line wires. 19 and 25 by a battery Q Transformer M isenergized by alternating current supplied to the same wires 19 and 25 byan alternating current source X. Impedance units 16 and 20, having ahigh impedance to alternating current but low resistance to directcurrent, obstruct the flow of alternating current from source X throughbattery Q and the winding of relay H respectively. Resistance units 76and 22 obstruct the flow of direct current from battery Q through sourceX and the primary winding 23 of transformer M, respectively.

The secondary winding 28 of transformer M supplies alternating currentto a rectifier R which in turn supplies direct current to the winding ofrelay N. As here shown, rectifier R comprises asymmetric units 29, 30,31 and 32, each of which may be similar to those disclosed and claimedin Letters Patent of the United States, No. 1,640,335, granted to L. O.Grondahl, August 23, 1927.

Having thus described, in general, the arrangement and location of thevarious parts comprising my invention, I will now describe the operationof the apparatus.

shown in the drawing, all parts are in their normal condition, that is,track sections AB, 13-0 and C-D are unoccupied, switches F anc A 2 areset in their normal position which is the position for directing trafficalong stretch Y only and not to or from siding Z, and all signals areindicating procoed. Signal S is indicating proceed because relay H isenergized in its normal direction by a circuit, shown in part, throughcontact 4 of relay G The circuit for operating signal S to its proceedposition passes from battery Q}, through wires 5, 10, 45 and 46, contact47 of relay P, wire 18, contact 49 of relay H wire 50, operatingmechanism of signal S and wire 52 back to battery Q With relay Henergized, relay P is energized by its circuit passing from battery Qthrough wires 5 and 6, contact 7 of relay H wire 8, winding of relay P,and wire 9 back to battery Q With relay P energized and relays G and Genergized, current of normal polarity is supplied for energizing relay Hby a circuit passing from battery Q}. through wires 5 and 10, contact 11of relay P, contact 12 of relay G impedance unit 16, wire 17, contact 18of relay G wire 19, impedance unit 20, winding of relay H wires 21, 25and 26, contact 27 of relay P, and wire 9 back to battery Q With relaysP and G energized, alternating current is supplied to the primary 23 oftransformer M by a circuit passing from source X, through wire 00,contact 74 of relay P, wire 75, resistance unit 76, wire 17 contact 18or relay G wire 19, resistance unit 22, primary winding 23, wires 24, 25and 78, contact 77 of relay P, and wire back to source X.

Vith alternating current flowing through primary winding 23, secondarywinding 28 of transformer M is supplying alternating current torectifier B which in turn supplies direct current for energizing relay Nby a circuit passing from rectifier R, through wire 33, contact 34 ofrelay H wire 35, winding of relay N, and wire 36 back to rectifier R.iVith relay N thus energized and with relay energized, current of normalpolarity is supplied for energizing relay H by its circuit passing froma battery Q through wire 37, contact 38 of relay N, wire 39, contact ofrelay G wire 41, winding of relay H Wire 42, contact as of relay N, andwire 1 1 back to battery Q The circuit for causing signal S to indicateproceed is now closed and passes from a battery Q through wire 59,contacts 60 and 61 of relay H wire 62, operating mechanism of signal Sand wire 64 back to battery Q The proceed indication control circuit forsignal S is similarly controlled by contacts 54: and of relay H I willnow assume that, with all parts thus in their normal condition, awestbound train enters section CD, tie-energizing relay G which thenopens the circuit for relay H wires 69 and 9 back to battery Q}.

causing signal S to indicate stop. As the train proceeds further andenters section BC, relay G becomes tie-energized, opening the circuitpreviously traced for relay H and the primary winding 23 of transformerM. Relay H upon becoming. tie-energized, opens its contact 3% in thecircuit already traced for relay N, which, on account of thedc-energization of transformer M, is already tie-energized and opens itsfront contacts and closes its back contacts 38 and 43.

As the train leaves section (l -D, relay H becomes energized in itsreverse direction by current flowing from battery Q through wire 37,'contact' l3" of relay N, wire 2, winding of relay H wire 4-1, contact40 of relay G wire 39, contact 38 of relay N, and wire 44 back tobattery Q With relay H energized in its reverse direction, signal S is,

now operated to its caution position by its circuit passing frombatteryQ through wire 59, contacts and 61 of relay H wire 63, operatingmechanism of signal S and wire 6% back to battery Q As the train laterstarts into section AB, relay G closes its back contact 67, thuscompleting for a brief period, while contact 65 of relay P continuesclosed, a pick-up circuit for relay T passing from battery Q throughwires 5, 10 and as, contact 65 of relay P, wire 66, contact 67 of relayG wire 68, winding of relay T, and wires 69 and 9 back to battery 0}.Relay G upon becoming deenergized, opens, at its contact 4, the circuitfor-relay H and hence relay T, upon becoming energized, completes itsown stick circuit passing from battery Q through Wires 5 and 6, contact70 of relay H wire 71, contact 72 of relay T, wire 73, winding of relayT, and After a suiiicient interval of time has elapsed, slow releaserelay P opens its contact 65, thus breaking the pick-up circuit forrelay T which, however, continues energized by its stick circuit, asalready traced, while the train is proceeding through section AB.

When the train leaves section B C, relay H becomes. energizediin itsreverse direction by current flowing from battery Q through wires 5, 10and 15, contact 2? of relay P, wires 26, 25 and 21, winding of relay Himpedance unit 20, wire 19, contact 18 of relay G wire 17 impedance unit16, wire 15, contact 14 of relay T, wire 13, contact 11 of relay P, andwire 9 back to battery Q At the same time, alternating current issupplied to primary winding 23 or" transformer M by a circuit passingfrom source X, through wire 00, contact 7 9 of relay T, wire 80,resistance unit 76, wire 17, and thence by the circuit previously tracedfor primary winding 23 to wire 25, and from there through wire 82,contact 81 of relay T, and wire 0 back to source X. VVithrelay H nowenergized in its reverse direction, the arm of signal S is operated tothe caution position by its circuit passing from battery Q through wire53, contacts 54 and 55 of relay H Wire 57, open ating mechanism ofsignal S, and wire 58 back to battery Q On account of transformer Mbeing supplied with alternating current and contact 34 of relay H beingclosed, relay N is energized, and hence relay H is again energized inits normal direction, causing the arm of signal S to be returned to itsproceed position.

hen the train leaves section A-B, permitting relay G to again becomeenergized, and assuming that signal relay H now becomes energized in itsreverse direction causing relay P to again become energized, current ofnormal polarity will again'be supplied to relay H by the circuitpreviously traced, thus causing signal S to again display the proceedindication. With relay H energized in the reverse direction, the arm ofsignal S is operated to the caution position by a circuit passing frombattery Q through wires 5, 10, 45 and 46, contact 47 of relay P, wire48, contact 49 of relay H wire 51, operating mechanism of signal S andWire 52 back to battery Q \Vhcn relay H again becomes energized in itsnormal direction after the train has passed a sufficient distance beyondsignal S the proceed indication will again be displayed by signal S asalready described.

I wiil now assume that with all parts again in their normal condition,an eastbound train de-ener izes relay H causing signal S to indicatestop and relay P to become de-energized. lVith relay P de-energized, andwith relays G and G energized, current of reverse polarity is nowsupplied to relay H by the circuit previously traced, except includingcontact 12 of relay G instead of the branch path through contact 14 ofrelay T. The circuit for primary winding 23 of transformer M is,however, open. With relay H energised in its reverse direction, signal Swill indicate caution, and with relay N deenergized on account ofprimary winding 23 of transformer M being de-energized, relay H will besupplied with current of reverse polarity, and hence signal S as well assignal S will indicate caution.

hen the train enters section AB, relav G becomes de-energized, openingthe circuit for relay H and thereby causing the arm of signal S to beoperated to its stop position while the arm of signal S continues'toindicate caution. The arm of signal S will remain in this position untilthe train deonergizes relay G From the foregoing description and theaccompanying drawing, it is clear that the arm of signal S is operatedto the caution position as soon as a westbound train leaves section B-Cbut that it is operated to the stop position as soon as aneastbound'train enters section AB, and thus the caution indication ofsignal S is controlled through section B-G only, for following trainmovements, but is provided with overlap control through section AB, foropposing train movements, whereas, in common terms of absolutepermissive block signaling, overlap control of the caution indication ofsignals S and S is provided for both following and opposing trainmovements.

From the foregoing description and the accompanying drawing, it is alsoclear that the proceed indication oi" signal S is interrupted when aneastbound train de-energizes relay H but that With a westbound trafiicmovement signal S displays its proceed indication as soon as the trainleaves section BC.

Although I have herein shown and described only one form of railwaysignaling apparatus embodying my'invention, it is understood thatvarious changes and modifications may be made therein within the scopeof the appended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track comprising a first and asecond section, a first signal, a second signal, a control circuit forsaid first signal controlled bytraftic conditions in said first sectionand energized by current from a direct current source, and a controlcircuit for said second signal including the wires of said first signalcontrol circuit and controlled by traftic conditions in said secondsection and energized by current from an alternating current source.

2. In combination, a stretch of railway track comprising a first and asecond section, a first signal, a seconc signal, a control circuit forsaid first signal controlled by trafiic conditions in said first sectionand energized by current of a givencharacter, and a control circuit forsaid second signal including the wires of said first signal controlcircuit and controlled by traiiic conditions in said second section andenergized by current differing in character from the current b whichsaid first signal control circuit is energized.

3. In combination with a railway home signal, a distant signal for saidhome signal, aflcontrol circuit for said home signal energized bycurrent of a given character, and a control circuit for said distantsignal including the wires of said home signal control circuit andenergized by current differing in character from said home signalcontrol current and energized only while said home signal controlcircuit is energized.

4. In combination, a stretch of railway track comprising a first and asecond section, a first signal, a second signal, a pair of conductors,and means including current of given character and current of adiii'erent' character supplied to said conductors for selectivelycontrolling said first and second signals according to trafficconditions in said first and second sections, respectively.

5. In a railway signaling system, a passing siding connected with astretch of main railway track, a permissive signal for governing themovement of traffic in a given direction through that portion of saidstretch with which said siding is connected, an absolute signal for'overning the movement of traffic in said given direction away from thatportion of said stretch with which said siding is connected, means forcausing said permissive signal to indicate stop when traffic moving insaid given direction occupies that portion of said stretch which isbetween said permissive and absolute signals only, and means for causingsaid. permissive signal to indicate stop when trafiic moving in theopposite direction occupies a portion of said stretch in advance of saidabsolute signal as well. as when trafiic moving in said oppositedirection occupies that portion of said stretch which is between saidpermissive and absolute signals.

6. In a railway signaling system, two adjoining sections of railwaytrack, a track circuit for each of said sections each including a trackrelay, a first and a second and a third signal, a control relaycontrolled in part by a front contact of the first of said track relays,a slow release relay controlled by a front contact of said controlrelay, a stick relay,a pick-up circuit for said stickrelay controlledbyafront contact of said slow release relay and bya back contact of saidfirst track relay, a stick circuit for said stick relay controlled by aback contact of said control relay, means for controlling said firstsignal by said control relay and by said slow release relay, a first anda second conductor, a second control relay responsive to direct currentand connected across said conductors through an impedance unit havinghigh impedance to alternating current but low resistance to directcurrent, a direct current source connected across said conductorsthrough a front contact of each of said first and second track relaysand through pole-changing contacts of said slow release relay andthrough a seond impedance unit similar to said first impedance unit, abranch path around said front contact of said first track relay passingthrough a front contact of said stick relay, an alternating currentsource connected across said conductors through a resistance unit andthrough a front contact of said slow release relay and of said secondtrack relay, a branch path through a front contact of said stick relaypassing around said slow release relay contact in series with saidalternating current source, a third control relay energized when currentfrom said alternating current source is supplied to said conductorswhile said second control relay is energized, means for controlling saidsecond signal by said second control relay, a fourth control relayresponsive to the polarity of the current supplied to its winding, acontrol circuit for said fourth control relay supplied with current ofnormal or reverse polarity according as said third control relay isenergized or deenergized, and means for controlling said third signal bysaid fourth control relay.

7. In combination, a first and a second section of railway track, afirst and a second signal, a pair of conductors, a source of current, asecond source of current of different character from the current fromsaid first source, a control means responsive to current from said firstsource, a second control means responsive to current from said secondsource, means for supplying current from said first source to saidconductors according to traffic conditions in said first section, meansfor supplying current from said second source to said conductorsaccording to traffic conditions in said second section, means includingsaid conductors for supplying said first control means with current fromsaid first source, means including said conductors for supplying saidsecond control means with current from said second source, means forcontrolling said first signal by said first control means, and means forcontrolling said second signal by said second control means.

7 8. In combination, a first and a second section of railway track, afirst and a second signal, a pair of conductors, a source of current, asecond source of current of different character from the current fromsaid first source, a control means responsive to current from said firstsource, a second control means responsive to current from said secondsource but not to current from said first source, means for supplyingcurrent from said first source to said conductors according to trafiicconditions in said first section, means for supplying current from saidsecond source to said conductors according to traffic conditions in saidsecond section, means including said conductors for supplying said firstcontrol means with current from said first source, means including saidconductors for supplying said second control means with current fromsaid second source, means for controlling said first signal by saidfirst control means, and means for controlling said second signal bysaid second control means.

9. In combination, a first and a second section of railway track, afirst and a second signal, a pair of conductors, a source of current, asecond source of current of different character from the current fromsaid first source, a control means responsive to current from said firstsource, a second control means responsive to current from said secondsource, means for supplying current from said first source to saidconductors according to traffic conditions in said first section, meansfor supplying current from said second source to said conductorsaccording to traific conditions in said second section, means includingsaid conductors for supplying said first control means with current fromsaid first source, means including said conductors for supplying saidsecond control means with current from said second source, means forpreventing current from said first source from reaching said secondcontrol means, means for controlling said first signal by said firstcontrol means, and means for controlling said second signal by saidsecond control means.

10. In combination, a first and a second section of railway track, afirst and a second signal, a pair of conductors, a source of directcurrent, a source of alternating current, a control means responsive todirect current, a control means responsive to alternating current, meansfor supplying current from said first source to said conductorsaccording to traffic conditions in said first section, means forsupplying current from said second source to said conductors accordingto traific "conditions in said second section, an impedance unit forobstructing the flow of alternating current, a resistance unit, meansincluding said conductors for supplying said first control means withcurrent from said first source through said impedance unit, meansincluding said conductors for supplying said second control means withcurrent from said second source through said resistance unit, means forcontrolling said first signal by said first control means, and means forcontrolling said second signal by said second control means.

In testimony whereof I affix my signature.

CHARLES W. BELL.

